Conservative politicians in the modern world generally despise their own voters. They need them at election time, but they do not enjoy meeting them, and find their views on morals, migration, education, and crime embarrassing. This is a problem only when the voters find out. Even then, the supporters of right-wing parties are by their nature so loyal that they refuse to believe the truth, and carry on electing men and women who obviously dislike them and are bound to betray them.

In Britain, the leaders of the Conservative Party grew accustomed to this. They could fling any sort of insult in their voters’ faces, pursue all manner of left-wing or even socialist policies, and yet these long-suffering, mild, and kindly people would still support them. Then a small rival, the United Kingdom Independence Party (UKIP), began to nibble at their toes. UKIP was in many ways the Conservative Party in exile. On almost every subject, it stood with the Tory core. But for years, those voters loyally boycotted UKIP, which actively agreed with them, and stuck with the Tories, who scorned them, because the Tories were the party of their birth and upbringing.

So it was that David Cameron, the leader of the Conservative Party, felt safe to brush UKIP away like an annoying insect (back in 2006, when it was tiny). He sneered that it was “sort of a bunch of…fruitcakes and loonies and closet racists mostly.” I am not sure if the term “fruitcake” is current in North America, but in Britain it is a reference to the phrase “nutty as a fruitcake,” and is not generally meant as a compliment, delicious as our fruitcakes are.

At that stage, many Conservative voters had persuaded themselves that Mr. Cameron was a secret Thatcherite, hiding his true right-wingness for electoral purposes and planning to reveal his patriotic, handbag-wielding inner self once he was in office. Then, they forgave him almost anything. Now, they do not. They have learned a lot about him since then, not much of it good. So they were not quite so relaxed when, on the eve of major local elections in May this year, a Tory Cabinet member named Kenneth Clarke repeated the jibe.

Mr. Clarke, a genial, jazz-loving veteran who enjoys the rather fruity sound of his own voice, might have got away with it had he stopped there. But he did not. He then drawled that he was sure that “most of the UKIP people are perfectly nice when they are having a drink,” and added: “It is very tempting to vote for a collection of clowns or indignant, angry people.”

For a moment, national political discourse fell silent as the words sank in. And then legions of ancient, devoted Tories, who had spent decades stuffing envelopes, hammering on doors, and attending wearisome wine-and-cheese fundraising gatherings so as to put people like Mr. Clarke in office, turned to each other in wild surmise and asked: “Does he mean…us?”

He did. It was a small echo of the moment when, in 1914, a petulant and thwarted Kaiser Wilhelm dismissed the British Expeditionary Force, then obstructing his plans for world domination, as “a contemptible little army.” The name stuck in a way he did not mean it to. Until the last of them went to their reward, long decades after the Kaiser’s proud throne had passed away, the remaining veterans of that army still called themselves, with glowing pride, “The Old Contemptibles.” UKIP, meanwhile, is adopting “Send in the Clowns” as its marching song. These backfiring insults, of course, cannot be unsaid. Mr. Cameron has apologized, but his targets tend to think he has done so only because it cost him votes. He regrets saying it out loud, not thinking it.

As Mr. Cameron and Mr. Clarke have now found out, loyalty cannot be counted on under all circumstances. And when it crumbles at last, it is as if a mighty river has escaped from its banks and levees. Nobody can be sure where the flood will go, and it is hard to be certain that it can ever be contained again. Great dams and embankments that took centuries to build and great devotion to maintain have given way in a matter of hours. Who will put them back? Would it be worth the effort even if it were possible?

The triumph of UKIP is being minimized by the conformist choirs of conventional commentators in London. It is “just a blip.” It is “mid-term revolt,” and so on. Be cautious about accepting this analysis. These commentators are themselves part of the establishment that does not understand why it is dying. They will say anything rather than recognize that the backlash is in fact a long-delayed and irreversible confirmation of a crucial truth.

WE ALL KNOW the difficulties involved in putting lipstick on a pig. But for years the effort to keep the Conservative Party in contention has involved slapping and smearing the entire contents of a cosmetics counter onto the ghastly countenance of a living cadaver. It has worked until now, to the extent that the Tories have been taken seriously as a party, long after they should have collapsed. But they have not won a national election since 1997, and there is now no good reason to believe they will ever win one again.

This fact has been obvious for many years to the few who actually study the details of opinion polls. But it had not penetrated the public mind until UKIP took roughly a quarter of the votes in county polls (only a couple of percentage points behind the official Tories). It also pushed David Cameron’s party into a bad third place in the South Shields special election, in Labour-dominated northeastern England. This followed a similar feat in the Eastleigh special election at the end of February, where—in a much more Tory area—UKIP also overtook the Conservatives.

These results demonstrate two fascinating things.

The first is that hundreds of thousands of formerly reliable Tory voters are now prepared to vote for another party. This will have involved them in a great deal of conscience-searching. They did not do it lightly. They would never have done it before. They have crossed a barrier of morals and habits that amounts to the breaking of a taboo.

It is unwise to assume that they will all come shyly back to the Tories when a general election arrives, almost certainly in 2015. Some will. But many will not. Others are still deciding. As it is increasingly clear that the Tories will lose the next general election whatever they do, voters are freed from the argument that they must vote Tory to keep Labour out. This plea is not very appealing anyway, since it is increasingly hard to tell the current Tory-Liberal Democrat coalition from a Labour government—except that the coalition has made far deeper cuts in the armed forces than Labour would ever have dared to do.

The second change is that an interesting number of non-Tory voters are prepared to vote for UKIP. These are former Labour and Liberal supporters who hate Margaret Thatcher’s memory and would rather cook and eat their own grandmothers than vote Conservative. But they do not associate UKIP with the Thatcher era.

So, vaguely beginning to form in the electoral air is a specter of elections yet to come, which must haunt the nightmares of all the existing parties and of the modern liberal establishment. What if all the morally and socially conservative people in Britain were to unite across class barriers and demand an end to the cultural revolution that has transformed their lives for the worse since the 1960s? What if a new electoral force came into being that did not just call itself conservative, but actually was conservative? What if a government came into office that had genuine intellectual and moral objections to the left-wing project of multiculturalism, economic liberalism, sexual revolution, and open borders, which has had the West in its grip for half a century?

THIS IS ONLY really an issue in the nations of the Anglosphere, which is to say, the countries that are the inheritors of Magna Carta, trial by jury, and habeas corpus. Conservative politics and sentiments exist only in those unusual countries where contentment is—or rather was—a natural state of being. Less happy lands have Christian Democrats, Agrarians, or Gaullists. The theory was that conservatism was a disposition, not a dogma. It did not need to have any ideas; in fact it was actively suspicious of them. It could simply apply common sense, much as Edmund Burke might have done: enthusiastic about the American Revolution, pessimistic about the French Revolution, and so on. But despite Burke’s prescience and understanding, the French Revolution was not fully reversed, nor were its beliefs finally defeated. On the contrary, political idealism replaced Christianity as the main intellectual force in the civilized world. Various forms of radical utopianism seized the minds of the brilliant and the ambitious, even in fortunate free countries. Repeated wars, in which the power of the state was advanced out of necessity, speeded this process. Nominally conservative parties met radical reformers—Fabian socialists, multiculturalists, egalitarians, and the politically correct movement—in the spirit of sensible compromise. The reformers pocketed their concessions and then came back for more. They moved on from social democracy to cultural and moral change, and to internationalism and globalism. By the end of the 20th century, the accumulated concessions amounted to a transformation as great, in its way, as a revolution.

The places where conservatism was bred and taught were themselves destroyed, subverted, or besieged by radicalism. Without an intellectual understanding of the left and its nature, conservatism was doomed to cooperate in its own destruction. And yet it still held on to millions of voters, whose views were vaguely soothed at elections and ignored the rest of the time. These millions did not like the changes that invaded their lives, but they had no coherent way of expressing their dismay and apprehension. Deference and trust were in their nature, so they assumed that those in charge of political conservatism knew what they were doing. It was only this, the deep magic of loyalty, that prevented a breach before now.

Almost the whole Anglosphere has gone through a parallel process. Australia and Canada have each had their own crisis of conservatism: Pauline Hanson’s One Nation briefly challenged Australia’s main conservative party but was cunningly outflanked by John Howard, who successfully portrayed himself as being a good deal more right-wing than he actually was. Preston Manning’s Reform Party—the most impressive such revolt—at one stage seemed likely to supplant Canada’s Tories. America’s Tea Party movement had similarities to both of these. But again it dribbled away into the dry soil.

Will UKIP be different? Its very interesting leader makes it possible that it may be. Nigel Farage (oddly, for such a very English person, it rhymes with “barrage” rather than with “carriage”) personally symbolizes a certain British spirit. He is happy, even eager, to be photographed with a half-empty (or is it half-full?) glass of beer in his hand. And by “beer” I mean the proper tepid, flat liquid, pumped into the glass by hand through yards of slimy tube, known in England as “bitter” and served by the pint, not in foreign liters.

He is a committed smoker (despite having survived testicular cancer). If there were an Olympic long lunch contest, he would be a gold medalist. Though he attended one of the more illustrious English private schools—Dulwich College, which also nurtured P.G. Wodehouse and Raymond Chandler—he is not really part of any establishment. His voice is a kind of bray, as those who have seen his attention-seeking public attack on European Council president Herman Van Rompuy will know. (Mr. Farage, a fine self-publicist, had no doubt noticed that a similar verbal machine-gunning of the then Labour premier Gordon Brown by an ambitious Tory called Daniel Hannan had garnered a large YouTube audience.)

Experts on English vocal snobbery would instantly be able to tell that he is not, as they say “out of the top drawer.” He looks like a frog who has long ago given up hope of being kissed by a princess, and doesn’t much mind. Most of his charm derives from the fact that he doesn’t pretend to be what he is not. Either that or he is a very good actor indeed. If he is a thinker, he is clever enough to conceal it from a public that mistrusts intellectual politicians. Apart from the smoking and the beer, his life is a living, breathing (or rather, wheezing) rejection of political correctness. He is not embarrassed to visit lap-dancing clubs. One would expect him to ask for extra lead in his gasoline and extra tar in his cigarettes. He was exposed in a downmarket newspaper (which did him no harm at all) for allegedly sharing an energetic night of passion with a Latvian woman, not his wife, an episode about which he seems to be both proud and embarrassed. He has been run over while far from sober, and narrowly escaped death when a light plane in which he was flying crashed (the plane was towing a UKIP campaign banner, which somehow got tangled in the tailplane). Claims that he is some sort of foreigner-hating xenophobe crumble when it is pointed out that he has French ancestry and that his (second) wife is German.

This combination—raffish, irrepressible, and troublesome—greatly appeals to that part of the British population weary of being bossed around by “Equality and Diversity” inspectors, tired of being banned from doing things they used to like, sick of the green tyranny that forces them to pay heavy charges for useless, ugly wind farms, and deeply mistrustful of the bland, evasive career politicians who have now taken over the three supposedly “mainstream” parties. These are, in fact, much less mainstream than Nigel Farage, and many of their policies are actually rather peculiar (see windmills, above, for a good example). Farage embodies something indomitable, irreverent, commonsensical, and entirely British that is instinctively liked by many, whatever their political views. Behind him stands a party that has little substance and many possible embarrassments. Mr. Farage himself is not a social conservative (he has mused in public about “decriminalizing” drugs), though quite a lot of his supporters are and he will sooner or later have to face this. But my guess is that he is a demolition man, not a builder. His task is to destroy. He is a missile directed straight at the heart of David Cameron’s Tory Party. And when he has finished exploding he may, with luck, have cleared a space for the creation of something Britain has never really had but now badly needs: a truly conservative party, dedicated to national independence, the rule of law, liberty of speech and thought, the sanctity of private life, and the married family. Whether anyone will take that opportunity is another matter.